Bonkers for bonobos

The superfans devoted to the zoo's once forgotten apes

In late April of 1960, the San Diego Zoo’s curator of mammals, George Pournelle, traveled to one of the most inaccessible parts of the African rainforest on a collecting expedition. His goal was to acquire a female okapi or two. The Belgian government had given the zoo a male okapi a few years later, but to get a mate for “Bayaku” required Pournelle to travel to Leopoldville (now Kinshasa) in the Congo, then take a boat for more than 1000 miles up the Congo River. From Stanleyville, he and the manager of the Leopoldville Zoo jounced overland for 300 miles to reach the Ituri Forest, which Pournelle later described as a “vast brooding wilderness…still avoided by the native tribes that live on its fringes…. Only the Pygmies venture into the dark recesses, and even they speak in hushed tones of the howling spirit that roams its depths on certain nights….”

Why does the zoo hide them?

Image by Katarzyna Sadej

At the Epulu Game Station, Pournelle and his companion eventually got two female specimens of the rare cousin to the giraffe. They crated them and trucked them back to Stanleyville. Because a DC-6 had recently crashed in the area, their chartered plane had been pressed into service to replace it, and the zoo men had to rustle up another DC-6 from Rhodesia. Eventually they loaded it with the okapis and other animals, including a tiny bonobo named Kakowet. If you go to the zoo’s bonobo exhibit today, you can see four of his direct descendants.

In recent years, scientists have determined that bonobos, along with chimpanzees, are humanity’s closest animal relative. We share more than 98 percent of our DNA with both species. But the bonobos’ range, limited to an area south of the Congo River, is far more restricted than that of chimps, who live on the other side of the river, and bonobos today are far more endangered. About 15,000 are estimated to remain in the wild, whereas chimpanzee estimates are between 170,000 and 300,000.

Lisa and Belle. “Lisa gave me a look, and it was intentional. That was her way of acknowledging me.”

Image by Mike Wilson

In 1960, almost nothing was known about these animals. Pournelle, though, had learned a bit about the tiny individual he later delivered to the Children’s Zoo. Someone had brought it to the Leopoldville Zoo on January 9, 1959, when it was only a few weeks old, nearly dead. Since the Congolese zoo had no nursery, and the zoo manager’s household was already hosting two other baby apes and “a very young leopard,” the manager gave the infant bonobo to a lady who showed up at the facility “asking for a nice young animal.” She visited the Leopoldville Zoo often with her little charge, which appeared to be thriving. But the woman one day shot her boyfriend dead in a fit of jealousy, and the zoo manager had to reclaim the young primate. His own children then looked after it until it was old enough to be transferred to the zoo grounds. Even there, Pournelle wrote in the December 1960 issue of Zoonooz, “[Kakowet] had special privileges and usually was allowed to roam about…. When he was tired of his explorations he always would return to the administration office for a handout — usually a bottle of cool refreshing pop.”

Raphaela Heesen: “I’ve never seen such intelligence.”

Image by Liz Sauer

Some confusion clouds Pournelle’s accounts in Zoonooz of the early life of Kakowet. (The name was a variation on cacahuète, the French word for “peanut.”) In his September 1960 article for the zoological society journal, Pournelle says that on the flight out of Africa, a baby gorilla “had the run of the plane and soon became fast friends with everyone, especially the crew.” Three months later, however, he refers only to Kakowet being on the long flight from the Congo, “allowed free run of the airplane” and becoming “friends with the entire Sabena crew.”

I have to assume that in the first article, the mammal curator was simply mixing up gorillas with bonobos. (The babies do look similar.) It’s a persistent error. On a recent visit, I heard one of the official zoo volunteers chat with visitors to the bonobo enclosure about the “gorillas” behind the glass.

Belle and big sister Maddie

Image by Liz Sauer

Reaching that enclosure is a great deal easier than traveling to the Congolese jungle. But it’s surprisingly hard to find, given what zoological crown jewels the bonobos are. The bonobo exhibit isn’t labeled on San Diego Zoo maps. To find it, you have to head down Treetops Way, past the flamingos and orangutans. At the intersection with the Hippo Trail, there’s a sign bearing an iconic gorilla image; the trail leads to the gorillas’ spacious home in the zoo’s “Lost Forest” section. Just past the first gorilla viewing area, there’s a stairway on your left leading down, but no hint of why one might want to descend it. At the bottom, another sign bears an image of some unidentified primate. If you don’t enter the aviary but instead turn right, you’ll come upon the first large window into the bonobos’ world.

Several signs around the enclosure do a good job of sharing information about bonobos, although the placards are easy to overlook. I’ve spent hours watching visitors stroll by. Many misidentify what they’re seeing. “Look! It’s a gorilla family,” I heard one little girl exclaim.

One of the last large mammals to become known, bonobos were first thought by scientists to be a smaller subspecies of chimpanzee. Indeed, the San Diego Zoo was still referring to them as “pygmy chimps” in 1980, the year Kakowet died. By the late 1920s, however, anatomists were pointing out the differences between chimps and bonobos; today the two are universally recognized to be separate species, with bonobos (pan paniscus) varying from chimps (pan troglodytes) as much as dogs do from coyotes. The two species behave quite differently. Male-dominated chimp societies are so aggressive, individuals sometimes murder each other. On occasion, chimpanzees engage in organized warfare. In contrast, no killing of one bonobo by another has been documented either in captivity or in the wild. Bonobos live in habitats so laden with fruit that some observers speculate they never had to fight over food. They developed an unusual strategy for defusing the tensions that might lead to violence: engaging in sex often and indiscriminately — males with females, females with females, males with males, young with old (and with each other).